Surgical shaft assemblies with slip ring assemblies with increased contact pressure

ABSTRACT

A slip ring assembly is usable with a surgical shaft assembly. The slip ring assembly includes a first connector flange comprising a conductor. The slip ring assembly further includes a second connector flange comprising a conductive element in contact with the conductor, wherein the second connector flange is rotatable relative to the first connector flange. In addition, the slip ring assembly also includes a support member, wherein the second connector flange is sandwiched between the first connector flange and the support member, and wherein the support member is configured to apply a load onto the second connector flange to maintain the contact between the conductor and the conductive element.

TECHNICAL FIELD

The present disclosure relates to surgical instruments and, in various circumstances, to surgical stapling and cutting instruments and staple cartridges therefor that are designed to staple and cut tissue.

BACKGROUND

In a motorized surgical stapling and cutting instrument it may be useful to measure the position and velocity of a cutting member in an initial predetermined time or displacement to control speed. Measurement of position or velocity over an initial predetermined time or displacement may be useful to evaluate tissue thickness and to adjust the speed of the remaining stroke based on this comparison against a threshold.

While several devices have been made and used, it is believed that no one prior to the inventors has made or used the device described in the appended claims.

SUMMARY

In one aspect of the present disclosure, a slip ring assembly includes a first connector flange comprising a conductor. The slip ring assembly further includes a second connector flange comprising a conductive element in contact with the conductor, wherein the second connector flange is rotatable relative to the first connector flange. In addition, the slip ring assembly also includes a support member, wherein the second connector flange is sandwiched between the first connector flange and the support member, and wherein the support member is configured to apply a load onto the second connector flange to maintain the contact between the conductor and the conductive element.

In one aspect of the present disclosure, a surgical shaft assembly includes a proximal shaft portion that has a proximal connector that includes a plurality of conductors. The surgical shaft assembly also includes a distal shaft portion that includes a distal connector that includes a plurality of conductive elements each in contact with one of the plurality of conductors, wherein the distal connector is rotatable relative to the proximal connector. The distal shaft portion also includes a support member, wherein the distal connector is positioned between the proximal connector and the support member, and wherein the support member is configured to apply a load onto the distal connector to maintain the contact between the plurality of conductors and the plurality of conductive elements.

A slip ring assembly includes a slip ring including an annular conductor, and a commutator including a commutator body portion and a commutator arm extending from the commutator body portion, wherein the commutator arm comprises a conductive element in contact with the conductor, and wherein the commutator is rotatable relative to the slip ring. The slip ring assembly also includes a support member with a body portion including a cradle configured to receive and hold the commutator body portion, and an arm extending from the body portion, wherein the arm comprises a resilient member configured to maintain the contact between the conductor and the conductive element.

FIGURES

The novel features of the various aspects described herein are set forth with particularity in the appended claims. The various aspects, however, both as to organization and methods of operation may be better understood by reference to the following description, taken in conjunction with the accompanying drawings as follows:

FIG. 1 is a perspective view of a surgical instrument that has a shaft assembly and an end effector in accordance with one or more aspects of the present disclosure.

FIG. 2 is an exploded assembly view of a portion of the surgical instrument of FIG. 1 according to one aspect of this disclosure.

FIG. 3 is an exploded view of an end effector of the surgical instrument of FIG. 1 according to one aspect of this disclosure.

FIG. 4 is perspective view of an RF cartridge and an elongate channel adapted for use with the RF cartridge according to one aspect of the present disclosure.

FIG. 5 is an exploded assembly view of portions of the interchangeable shaft assembly of the surgical instrument of FIG. 1 according to one aspect of this disclosure.

FIG. 6 is another exploded assembly view of portions of the interchangeable shaft assembly of FIG. 1 according to one aspect of this disclosure.

FIG. 7 is a cross-sectional view of a portion of the interchangeable shaft assembly of FIG. 1 according to one aspect of this disclosure.

FIG. 8 is a perspective view of a portion of the shaft assembly of FIG. 1 with the switch drum omitted for clarity.

FIG. 9 is another perspective view of the portion of the interchangeable shaft assembly of FIG. 1 with the switch drum mounted thereon.

FIG. 10 is an exploded view of a slip ring assembly according to one aspect of this disclosure.

FIG. 11 is another exploded view of the slip ring assembly of FIG. 10.

FIG. 12 is a cross sectional view of the slip ring assembly of FIG. 10 depicting a new conductive element.

FIG. 13 is a cross sectional view of the slip ring assembly of FIG. 10 in depicting a fatigued and/or worn conductive element.

DESCRIPTION

Applicant of the present application owns the following U.S. Patent Applications that were filed on Jun. 28, 2017 and which are each herein incorporated by reference in their respective entireties:

U.S. patent application Ser. No. 15/635,628, entitled ARTICULATION STATE DETECTION MECHANISMS;

U.S. patent application Ser. No. 15/635,707, entitled SURGICAL SHAFT ASSEMBLIES WITH SLIP RING ASSEMBLIES FORMING CAPACITIVE CHANNELS;

U.S. patent application Ser. No. 15/635,734, entitled METHOD OF COATING SLIP RINGS;

U.S. patent application Ser. No. 15/635,768, entitled SURGICAL SHAFT ASSEMBLIES WITH WATERTIGHT HOUSINGS; and

U.S. patent application Ser. No. 15/635,790, entitled SURGICAL SHAFT ASSEMBLIES WITH FLEXIBLE INTERFACES.

Certain aspects are shown and described to provide an understanding of the structure, function, manufacture, and use of the disclosed devices and methods. Features shown or described in one example may be combined with features of other examples and modifications and variations are within the scope of this disclosure.

The terms “proximal” and “distal” are relative to a clinician manipulating the handle of the surgical instrument where “proximal” refers to the portion closer to the clinician and “distal” refers to the portion located further from the clinician. For expediency, spatial terms “vertical,” “horizontal,” “up,” and “down” used with respect to the drawings are not intended to be limiting and/or absolute, because surgical instruments can used in many orientations and positions.

The terms “comprise” (and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has” and “having”), “include” (and any form of include, such as “includes” and “including”) and “contain” (and any form of contain, such as “contains” and “containing”) are open-ended linking verbs. As a result, a surgical system, device, or apparatus that “comprises,” “has,” “includes” or “contains” one or more elements possesses those one or more elements, but is not limited to possessing only those one or more elements. Likewise, an element of a system, device, or apparatus that “comprises,” “has,” “includes” or “contains” one or more features possesses those one or more features, but is not limited to possessing only those one or more features.

Example devices and methods are provided for performing laparoscopic and minimally invasive surgical procedures. Such devices and methods, however, can be used in other surgical procedures and applications including open surgical procedures, for example. The surgical instruments can be inserted into a through a natural orifice or through an incision or puncture hole formed in tissue. The working portions or end effector portions of the instruments can be inserted directly into the body or through an access device that has a working channel through which the end effector and elongated shaft of the surgical instrument can be advanced.

FIGS. 1-9 depict a motor-driven surgical instrument 10 for cutting and fastening that may or may not be reused. In the illustrated examples, the surgical instrument 10 includes a housing 12 that comprises a handle assembly 14 that is configured to be grasped, manipulated, and actuated by the clinician. The housing 12 is configured for operable attachment to an interchangeable shaft assembly 200 that has an end effector 300 operably coupled thereto that is configured to perform one or more surgical tasks or procedures. In accordance with the present disclosure, various forms of interchangeable shaft assemblies may be effectively employed in connection with robotically controlled surgical systems. The term “housing” may encompass a housing or similar portion of a robotic system that houses or otherwise operably supports at least one drive system configured to generate and apply at least one control motion that could be used to actuate interchangeable shaft assemblies. The term “frame” may refer to a portion of a handheld surgical instrument. The term “frame” also may represent a portion of a robotically controlled surgical instrument and/or a portion of the robotic system that may be used to operably control a surgical instrument. Interchangeable shaft assemblies may be employed with various robotic systems, instruments, components, and methods disclosed in U.S. Pat. No. 9,072,535, entitled SURGICAL STAPLING INSTRUMENTS WITH ROTATABLE STAPLE DEPLOYMENT ARRANGEMENTS, which is herein incorporated by reference in its entirety.

FIG. 1 is a perspective view of a surgical instrument 10 that has an interchangeable shaft assembly 200 operably coupled thereto according to one aspect of this disclosure. The housing 12 includes an end effector 300 that comprises a surgical cutting and fastening device configured to operably support a surgical staple cartridge 304 therein. The housing 12 may be configured for use in connection with interchangeable shaft assemblies that include end effectors that are adapted to support different sizes and types of staple cartridges, have different shaft lengths, sizes, and types. The housing 12 may be employed with a variety of interchangeable shaft assemblies, including assemblies configured to apply other motions and forms of energy such as, radio frequency (RF) energy, ultrasonic energy, and/or motion to end effector arrangements adapted for use in connection with various surgical applications and procedures. The end effectors, shaft assemblies, handles, surgical instruments, and/or surgical instrument systems can utilize any suitable fastener, or fasteners, to fasten tissue. For instance, a fastener cartridge comprising a plurality of fasteners removably stored therein can be removably inserted into and/or attached to the end effector of a shaft assembly.

The handle assembly 14 may comprise a pair of interconnectable handle housing segments 16, 18 interconnected by screws, snap features, adhesive, etc. The handle housing segments 16, 18 cooperate to form a pistol grip portion 19 that can be gripped and manipulated by the clinician. The handle assembly 14 operably supports a plurality of drive systems configured to generate and apply control motions to corresponding portions of the interchangeable shaft assembly that is operably attached thereto.

FIG. 2 is an exploded assembly view of a portion of the surgical instrument 10 of FIG. 1 according to one aspect of this disclosure. The handle assembly 14 may include a frame 20 that operably supports a plurality of drive systems. The frame 20 can operably support a “first” or closure drive system 30, which can apply closing and opening motions to the interchangeable shaft assembly 200. The closure drive system 30 may include an actuator such as a closure trigger 32 pivotally supported by the frame 20. The closure trigger 32 is pivotally coupled to the handle assembly 14 by a pivot pin 33 to enable the closure trigger 32 to be manipulated by a clinician. When the clinician grips the pistol grip portion 19 of the handle assembly 14, the closure trigger 32 can pivot from a starting or “unactuated” position to an “actuated” position and more particularly to a fully compressed or fully actuated position.

The handle assembly 14 and the frame 20 may operably support a firing drive system 80 configured to apply firing motions to corresponding portions of the interchangeable shaft assembly attached thereto. The firing drive system 80 may employ an electric motor 82 located in the pistol grip portion 19 of the handle assembly 14. The electric motor 82 may be a DC brushed motor having a maximum rotational speed of approximately 25,000 RPM, for example. In other arrangements, the motor may include a brushless motor, a cordless motor, a synchronous motor, a stepper motor, or any other suitable electric motor. The electric motor 82 may be powered by a power source 90 that may comprise a removable power pack 92. The removable power pack 92 may comprise a proximal housing portion 94 configured to attach to a distal housing portion 96. The proximal housing portion 94 and the distal housing portion 96 are configured to operably support a plurality of batteries 98 therein. Batteries 98 may each comprise, for example, a Lithium Ion (LI) or other suitable battery. The distal housing portion 96 is configured for removable operable attachment to a control circuit board 100, which is operably coupled to the electric motor 82. Several batteries 98 connected in series may power the surgical instrument 10. The power source 90 may be replaceable and/or rechargeable.

The electric motor 82 can include a rotatable shaft (not shown) that operably interfaces with a gear reducer assembly 84 mounted in meshing engagement with a with a set, or rack, of drive teeth 122 on a longitudinally movable drive member 120. The longitudinally movable drive member 120 has a rack of drive teeth 122 formed thereon for meshing engagement with a corresponding drive gear 86 of the gear reducer assembly 84.

In use, a voltage polarity provided by the power source 90 can operate the electric motor 82 in a clockwise direction wherein the voltage polarity applied to the electric motor by the battery can be reversed in order to operate the electric motor 82 in a counter-clockwise direction. When the electric motor 82 is rotated in one direction, the longitudinally movable drive member 120 will be axially driven in the distal direction “DD.” When the electric motor 82 is driven in the opposite rotary direction, the longitudinally movable drive member 120 will be axially driven in a proximal direction “PD.” The handle assembly 14 can include a switch that can be configured to reverse the polarity applied to the electric motor 82 by the power source 90. The handle assembly 14 may include a sensor configured to detect the position of the longitudinally movable drive member 120 and/or the direction in which the longitudinally movable drive member 120 is being moved.

Actuation of the electric motor 82 can be controlled by a firing trigger 130 that is pivotally supported on the handle assembly 14. The firing trigger 130 may be pivoted between an unactuated position and an actuated position.

Turning back to FIG. 1, the interchangeable shaft assembly 200 includes an end effector 300 comprising an elongated channel 302 configured to operably support a surgical staple cartridge 304 therein. The end effector 300 may include an anvil 306 that is pivotally supported relative to the elongated channel 302. The interchangeable shaft assembly 200 may include an articulation joint 270. Construction and operation of the end effector 300 and the articulation joint 270 are set forth in U.S. Patent Application Publication No. 2014/0263541, entitled ARTICULATABLE SURGICAL INSTRUMENT COMPRISING AN ARTICULATION LOCK, which is herein incorporated by reference in its entirety. The interchangeable shaft assembly 200 may include a proximal housing or nozzle 201 comprised of nozzle portions 202, 203. The interchangeable shaft assembly 200 may include a closure tube 260 extending along a shaft axis SA that can be utilized to close and/or open the anvil 306 of the end effector 300.

Turning back to FIG. 1, the closure tube 260 is translated distally (direction “DD”) to close the anvil 306, for example, in response to the actuation of the closure trigger 32 in the manner described in the aforementioned reference U.S. Patent Application Publication No. 2014/0263541. The anvil 306 is opened by proximally translating the closure tube 260. In the anvil-open position, the closure tube 260 is moved to its proximal position.

FIG. 3 is an exploded view of one aspect of an end effector 300 of the surgical instrument 10 of FIG. 1 in accordance with one or more aspects of the present disclosure. The end effector 300 may include the anvil 306 and the surgical staple cartridge 304. In this non-limiting example, the anvil 306 is coupled to an elongated channel 302. For example, apertures 199 can be defined in the elongated channel 302 which can receive pins 152 extending from the anvil 306 and allow the anvil 306 to pivot from an open position to a closed position relative to the elongated channel 302 and surgical staple cartridge 304. A firing bar 172 is configured to longitudinally translate into the end effector 300. The firing bar 172 may be constructed from one solid section, or in various examples, may include a laminate material comprising, for example, a stack of steel plates. The firing bar 172 comprises an E-beam 178 and a cutting edge 182 at a distal end thereof. In various aspects, the E-beam may be referred to as an I-beam. A distally projecting end of the firing bar 172 can be attached to the E-beam 178 element in any suitable manner and can, among other things, assist in spacing the anvil 306 from a surgical staple cartridge 304 positioned in the elongated channel 302 when the anvil 306 is in a closed position. The E-beam 178 also can include a sharpened cutting edge 182 that can be used to sever tissue as the E-beam 178 is advanced distally by the firing bar 172. In operation, the E-beam 178 also can actuate, or fire, the surgical staple cartridge 304. The surgical staple cartridge 304 can include a molded cartridge body 194 that holds a plurality of staples 191 resting upon staple drivers 192 within respective upwardly open staple cavities 195. A wedge sled 190 is driven distally by the E-beam 178, sliding upon a cartridge tray 196 that holds together the various components of the surgical staple cartridge 304. The wedge sled 190 upwardly cams the staple drivers 192 to force out the staples 191 into deforming contact with the anvil 306 while the cutting edge 182 of the E-beam 178 severs clamped tissue.

The E-beam 178 can include upper pins 180 that engage the anvil 306 during firing. The E-beam 178 can further include middle pins 184 and a bottom foot 186 that can engage various portions of the cartridge body 194, cartridge tray 196, and elongated channel 302. When a surgical staple cartridge 304 is positioned within the elongated channel 302, a slot 193 defined in the cartridge body 194 can be aligned with a longitudinal slot 197 defined in the cartridge tray 196 and a slot 189 defined in the elongated channel 302. In use, the E-beam 178 can slide through the aligned longitudinal slots 193, 197, and 189 wherein, as indicated in FIG. 3, the bottom foot 186 of the E-beam 178 can engage a groove running along the bottom surface of elongated channel 302 along the length of slot 189, the middle pins 184 can engage the top surfaces of cartridge tray 196 along the length of longitudinal slot 197, and the upper pins 180 can engage the anvil 306. In such circumstances, the E-beam 178 can space, or limit the relative movement between, the anvil 306 and the surgical staple cartridge 304 as the firing bar 172 is moved distally to fire the staples from the surgical staple cartridge 304 and/or incise the tissue captured between the anvil 306 and the surgical staple cartridge 304. Thereafter, the firing bar 172 and the E-beam 178 can be retracted proximally allowing the anvil 306 to be opened to release the two stapled and severed tissue portions.

Referring to FIG. 4, in at least one arrangement, an interchangeable shaft assembly can be used in connection with an RF cartridge 1700 as well as a surgical staple/fastener cartridge.

The RF surgical cartridge 1700 includes a cartridge body 1710 that is sized and shaped to be removably received and supported in the elongate channel 1602. For example, the cartridge body 1710 may be configured to be removable retained in snap engagement with the elongate channel 1602. In at least one aspect, the cartridge body 1710 includes a centrally disposed elongate slot 1712 that extends longitudinally through the cartridge body to accommodate longitudinal travel of a knife therethrough.

The cartridge body 1710 is formed with a centrally disposed raised electrode pad 1720. The elongate slot 1712 extends through the center of the electrode pad 1720 and serves to divide the pad 1720 into a left pad segment 1720L and a right pad segment 1720R. A right flexible circuit assembly 1730R is attached to the right pad segment 1720R and a left flexible circuit assembly 1730L is attached to the left pad segment 1720L. In at least one arrangement for example, the right flexible circuit 1730R comprises a plurality of wires 1732R that may include, for example, wider wires/conductors for RF purposes and thinner wires for conventional stapling purposes that are supported or attached or embedded into a right insulator sheath/member 1734R that is attached to the right pad 1720R. In addition, the right flexible circuit assembly 1730R includes a “phase one”, proximal right electrode 1736R and a “phase two” distal right electrode 1738R. Likewise, the left flexible circuit assembly 1730L comprises a plurality of wires 1732L that may include, for example, wider wires/conductors for RF purposes and thinner wires for conventional stapling purposes that are supported or attached or embedded into a left insulator sheath/member 1734L that is attached to the left pad 1720L. In addition, the left flexible circuit assembly 1730L includes a “phase one”, proximal left electrode 1736L and a “phase two” distal left electrode 1738L. The left and right wires 1732L, 1732R are attached to a distal micro-chip 1740 mounted to the distal end portion of the cartridge body 1710.

The elongate channel 1602 includes a channel circuit 1670 that is supported in a recess 1621 that extends from the proximal end of the elongate channel 1602 to a distal location 1623 in the elongate channel bottom portion 1620. The channel circuit 1670 includes a proximal contact portion 1672 that contacts a distal contact portion 1169 of a flexible shaft circuit strip for electrical contact therewith. A distal end 1674 of the channel circuit 1670 is received within a corresponding wall recess 1625 formed in one of the channel walls 1622 and is folded over and attached to an upper edge 1627 of the channel wall 1622. A serial of corresponding exposed contacts 1676 are provided in the distal end 1674 of the channel circuit 1670. An end of a flexible cartridge circuit 1750 is attached to the distal micro-chip 1740 and is affixed to the distal end portion of the cartridge body 1710. Another end is folded over the edge of the cartridge deck surface 1711 and includes exposed contacts configured to make electrical contact with the exposed contacts 1676 of the channel circuit 1670. Thus, when the RF cartridge 1700 is installed in the elongate channel 1602, the electrodes as well as the distal micro-chip 1740 are powered and communicate with an onboard circuit board through contact between the flexible cartridge circuit 1750, the flexible channel circuit 1670, a flexible shaft circuit and slip ring assembly.

FIG. 5 is another exploded assembly view of portions of the interchangeable shaft assembly 200 according to one aspect of this disclosure. The interchangeable shaft assembly 200 includes a firing member 220 that is supported for axial travel within a shaft spine 210. The firing member 220 includes an intermediate firing shaft portion 222 that is configured for attachment to a distal portion or bar 280. The intermediate firing shaft portion 222 may include a longitudinal slot 223 in the distal end thereof which can be configured to receive a tab 284 on the proximal end 282 of the distal bar 280. The longitudinal slot 223 and the proximal end 282 can be sized and configured to permit relative movement therebetween and can comprise a slip joint 286. The slip joint 286 can permit the intermediate firing shaft portion 222 of the firing member 220 to be moved to articulate the end effector 300 without moving, or at least substantially moving, the bar 280. Once the end effector 300 has been suitably oriented, the intermediate firing shaft portion 222 can be advanced distally until a proximal sidewall of the longitudinal slot 223 comes into contact with the tab 284 in order to advance the distal bar 280. Advancement of the distal bar 280 causes the E-beam 178 to be advanced distally to fire the staple cartridge positioned within the channel 302.

Further to the above, the shaft assembly 200 includes a clutch assembly 400 which can be configured to selectively and releasably couple the articulation driver 230 to the firing member 220. In one form, the clutch assembly 400 includes a lock collar, or sleeve 402, positioned around the firing member 220 wherein the lock sleeve 402 can be rotated between an engaged position in which the lock sleeve 402 couples the articulation drive 230 to the firing member 220 and a disengaged position in which the articulation drive 230 is not operably coupled to the firing member 220. When lock sleeve 402 is in its engaged position, distal movement of the firing member 220 can move the articulation drive 230 distally and, correspondingly, proximal movement of the firing member 220 can move the articulation drive 230 proximally. When lock sleeve 402 is in its disengaged position, movement of the firing member 220 is not transmitted to the articulation drive 230 and, as a result, the firing member 220 can move independently of the articulation drive 230.

The lock sleeve 402 can comprise a cylindrical, or an at least substantially cylindrical, body including a longitudinal aperture 403 defined therein configured to receive the firing member 220. The lock sleeve 402 can comprise diametrically-opposed, inwardly-facing lock protrusions 404 and an outwardly-facing lock member 406. The lock protrusions 404 can be configured to be selectively engaged with the firing member 220. More particularly, when the lock sleeve 402 is in its engaged position, the lock protrusions 404 are positioned within a drive notch 224 defined in the firing member 220 such that a distal pushing force and/or a proximal pulling force can be transmitted from the firing member 220 to the lock sleeve 402. When the lock sleeve 402 is in its engaged position, the second lock member 406 is received within a drive notch 232 defined in the articulation driver 230 such that the distal pushing force and/or the proximal pulling force applied to the lock sleeve 402 can be transmitted to the articulation driver 230. In effect, the firing member 220, the lock sleeve 402, and the articulation driver 230 will move together when the lock sleeve 402 is in its engaged position. On the other hand, when the lock sleeve 402 is in its disengaged position, the lock protrusions 404 may not be positioned within the drive notch 224 of the firing member 220 and, as a result, a distal pushing force and/or a proximal pulling force may not be transmitted from the firing member 220 to the lock sleeve 402. Correspondingly, the distal pushing force and/or the proximal pulling force may not be transmitted to the articulation driver 230. In such circumstances, the firing member 220 can be slid proximally and/or distally relative to the lock sleeve 402 and the proximal articulation driver 230.

The shaft assembly 200 further includes a switch drum 500 that is rotatably received on the closure tube 260. The switch drum 500 comprises a hollow shaft segment 502 that has a shaft boss 504 formed thereon for receive an outwardly protruding actuation pin 410 therein. In various circumstances, the actuation pin 410 extends through a slot 267 into a longitudinal slot 408 provided in the lock sleeve 402 to facilitate axial movement of the lock sleeve 402 when it is engaged with the articulation driver 230. A rotary torsion spring 420 is configured to engage the boss 504 on the switch drum 500 and a portion of the nozzle housing 203 as shown in FIG. 5 to apply a biasing force to the switch drum 500. The switch drum 500 can further comprise at least partially circumferential openings 506 defined therein which, referring to FIGS. 5 and 6, can be configured to receive circumferential mounts extending from the nozzle halves 202, 203 and permit relative rotation, but not translation, between the switch drum 500 and the proximal nozzle 201. The mounts also extend through openings 266 in the closure tube 260 to be seated in recesses 211 in the shaft spine 210. However, rotation of the nozzle 201 to a point where the mounts reach the end of their respective openings 506 in the switch drum 500 will result in rotation of the switch drum 500 about the shaft axis SA-SA. Rotation of the switch drum 500 will ultimately result in the rotation of the actuation pin 410 and the lock sleeve 402 between its engaged and disengaged positions. Thus, in essence, the nozzle 201 may be employed to operably engage and disengage the articulation drive system with the firing drive system in the various manners described in further detail in U.S. patent application Ser. No. 13/803,086.

The shaft assembly 200 can comprise a slip ring assembly 600 which can be configured to conduct electrical power to and/or from the end effector 300 and/or communicate signals to and/or from the end effector 300, for example. The slip ring assembly 600 can comprise a proximal connector flange 604 mounted to a chassis flange 242 extending from the chassis 240 and a distal connector flange 601 positioned within a slot defined in the nozzle halves 202, 203. The proximal connector flange 604 can comprise a first face and the distal connector flange 601 can comprise a second face which is positioned adjacent to and movable relative to the first face. The distal connector flange 601 can rotate relative to the proximal connector flange 604 about the shaft axis SA-SA. The proximal connector flange 604 can comprise a plurality of concentric, or at least substantially concentric, conductors 602 defined in the first face thereof. A connector 607 can be mounted on the proximal side of the connector flange 601 and may have a plurality of contacts, wherein each contact corresponds to and is in electrical contact with one of the conductors 602. Such an arrangement permits relative rotation between the proximal connector flange 604 and the distal connector flange 601 while maintaining electrical contact therebetween. The proximal connector flange 604 can include an electrical connector 606 which can place the conductors 602 in signal communication with a circuit board mounted to the shaft chassis 240, for example. In at least one instance, a wiring harness comprising a plurality of conductors can extend between the electrical connector 606 and the circuit board. U.S. patent application Ser. No. 13/800,067, entitled STAPLE CARTRIDGE TISSUE THICKNESS SENSOR SYSTEM, filed on Mar. 13, 2013, is incorporated by reference in its entirety. U.S. patent application Ser. No. 13/800,025, entitled STAPLE CARTRIDGE TISSUE THICKNESS SENSOR SYSTEM, filed on Mar. 13, 2013, is incorporated by reference in its entirety. Further details regarding slip ring assembly 600 may be found in U.S. patent application Ser. No. 13/803,086.

The shaft assembly 200 can include a proximal portion which is fixably mounted to the handle assembly 14 and a distal portion which is rotatable about a longitudinal axis. The rotatable distal shaft portion can be rotated relative to the proximal portion about the slip ring assembly 600. The distal connector flange 601 of the slip ring assembly 600 can be positioned within the rotatable distal shaft portion. Moreover, further to the above, the switch drum 500 can also be positioned within the rotatable distal shaft portion. When the rotatable distal shaft portion is rotated, the distal connector flange 601 and the switch drum 500 can be rotated synchronously with one another. In addition, the switch drum 500 can be rotated between a first position and a second position relative to the distal connector flange 601. When the switch drum 500 is in its first position, the articulation drive system may be operably disengaged from the firing drive system and, thus, the operation of the firing drive system may not articulate the end effector 300 of the shaft assembly 200. When the switch drum 500 is in its second position, the articulation drive system may be operably engaged with the firing drive system and, thus, the operation of the firing drive system may articulate the end effector 300 of the shaft assembly 200. When the switch drum 500 is moved between its first position and its second position, the switch drum 500 is moved relative to distal connector flange 601.

In various examples, the shaft assembly 200 can comprise at least one sensor configured to detect the position of the switch drum 500. The distal connector flange 601 can comprise a Hall effect sensor 605, for example, and the switch drum 500 can comprise a magnetic element, such as permanent magnet 505, for example. The Hall effect sensor 605 can be configured to detect the position of the permanent magnet 505. When the switch drum 500 is rotated between its first position and its second position, the permanent magnet 505 can move relative to the Hall effect sensor 605. In various examples, Hall effect sensor 605 can detect changes in a magnetic field created when the permanent magnet 505 is moved. The Hall effect sensor 605 can be in signal communication with a control circuit, for example. Based on the signal from the Hall effect sensor 605, a microcontroller on the control circuit can determine whether the articulation drive system is engaged with or disengaged from the firing drive system.

Referring to FIG. 10, a slip ring assembly 1200 is illustrated. The slip ring assembly 1200 is similar in many respects to the slip ring assembly 600. For example, the slip ring assembly 1200 can be configured to conduct electrical power to and/or from the surgical end effector 300 and/or communicate signals to and/or from the surgical end effector 300, back to an onboard circuit board, while facilitating rotational travel of a distal shaft portion of a shaft assembly relative to a proximal shaft portion of the shaft assembly. A shaft assembly 200 can be equipped with the slip ring assembly 1200 in lieu of the slip ring assembly 600, for example.

In the example of FIGS. 10-13, the slip ring assembly 1200 includes a slip ring or proximal connector flange 1201, which can be mounted to the chassis flange 242 (FIG. 8), and a commutator or distal connector flange 1211 received, held, and/or supported in a cradle 1229 defined in a support or bracket member 1221. As illustrated in FIG. 10, the distal connector flange 1211 is sandwiched, or at least partially sandwiched, between the proximal connector flange 1201 and the bracket member 1221.

The proximal connector flange 1201 comprises a proximal side 1202 and a distal side 1203. Likewise, the distal connector flange 1211 comprises a proximal side 1212 and a distal side 1213. Also, the bracket member 1221 comprises a proximal side 1222 and a distal side 1223. The proximal side 1212 of the distal connector flange 1211 is positioned adjacent to and movable relative to the distal side 1203 of the proximal connector flange 1201. The distal side 1213 of the distal connector flange 1211 is positioned adjacent to and is supported by a proximal side 1222 of the bracket member 1221.

A shaft assembly such as, for example, the shaft assembly 200 can be equipped with the slip ring assembly 1200. In some examples, the proximal side 1202 of the proximal connector flange 1201 can be fixed to a proximal shaft portion of a shaft assembly. In addition, the distal side 1223 of the bracket member 1221 can be fixed to a distal shaft portion of the shaft assembly. Accordingly, in such examples, a user-controlled rotation of the shaft assembly causes the distal connector flange 1211 and the bracket member 1221 to be rotated with the distal shaft portion relative to the proximal connector flange 1201 and the proximal shaft portion. Like the proximal connector flange 604, the proximal connector flange 1201 comprises a plurality of concentric, or at least substantially concentric, conductors 1205 defined in the distal side 1203 thereof. In some examples, the conductors 1205 may comprise an annular or circular shape. As illustrated in FIG. 10, connectors 1214 can be mounted on the proximal side 1212 of the distal connector flange 1211 and may have a plurality of conductors or conductive elements 1215, wherein each conductive element 1214 corresponds to and is in contact with one of the conductors 1205 of the proximal connector flange 1201. Such an arrangement permits relative rotation between the proximal connector flange 1201 and the distal connector flange 1211 while maintaining electrical contact therebetween. The proximal connector flange 1201 can include an electrical connector which can place the conductors 1205 in signal communication with a circuit board which can be mounted to the shaft chassis 240, for example.

In various instances, the electrically conductive elements 1215 can be in the form of resiliently biased pins, resiliently biased leaf springs, resiliently biased lever arms with end contacts, and/or any other spring contacts as will be apparent to one of ordinary skill in the art in view of the teachings herein. A conductive element 1215 may include a silver graphite tip on the end of a beryllium copper leaf spring or a metallic gold alloy wire, for example. In the example of FIG. 10, the conductive elements 1214 are in the form of resiliently biased leaf springs. When the slip ring assembly 1200 is assembled, the conductive elements 1214 experience a compressive load governed, in part, by the resiliency of the conductive elements 1214 and a distance (d₁) between the proximal connector flange 1201 and the connectors 1214 of the distal connector flange 1211, as illustrated in FIG. 12. The compressive load causes the conductive elements 1214 to apply and maintain a pressure against the conductors 1205 sufficient to establish an electrical connection capable of transmitting signals and/or power between the proximal connector flange 1202 and the distal connector flange 1211.

Over time, however, due to fatigue and/or wear of the conductive elements 1215, the pressure applied by the conductive elements 1215 against the conductors 1205 decreases which causes a reduction in the quality of signal and/or power transmission between the proximal connector flange 1202 and the distal connector flange 1211. The slip ring assembly 1200 compensates for the loss of pressure caused by the fatigue and/or wear of the conductive elements 1215. As illustrated in FIG. 13, the bracket member 1221 maintains the pressure applied by the conductive elements 1215 at or above a desired threshold by decreasing the distance between the proximal connector flange 1201 and the connectors 1214 of the distal connector flange 1211 to a distance (d₂).

In the example illustrated in FIGS. 10-13, the bracket member 1221 includes a body portion 1226 and arms 1227 extending from the body portion 1226. Likewise, the distal connector flange 1211 includes a body portion 1216 and arms 1217 extending from the body portion 1216. The arms 1227 of the bracket member 1221 are equipped with resilient members 1228 that apply a compressive load against the arms 1217 of the distal connector flange 1211 to maintain, or at least substantially maintain, the pressure applied by the conductive elements 1215 against the conductors 1205 at, or at least substantially at, a desired pressure regardless of the fatigue or wear that can be experienced by the conductive elements 1215.

Referring to FIG. 13, a resilient member 1228 has moved an arm 1217 of a distal connector flange 1211 a distance (d₃) to maintain, or at least substantially maintain, the pressure applied by the conductive elements 1215 against the conductors 1205 at, or at least substantially at, the desired pressure. Initially, the forces applied to the distal connector flange 1211 are balanced. Over time, however, as the conductive elements 1215 experience wear and/or fatigue, the forces applied to the distal connector flange 1211 become unbalanced in favor of the resilient members 1228. In order to re-achieve the balance, the distal connector flange 1211 is shifted the distance (d₃). In certain instances, the arms 1217 can bend with respect to the body portion 1216 under the load applied by the resilient members 1228. In other instances, the cradle 1229 is configured to allow a slight tilting of the body portion 1216 to re-achieve the balance. In the arrangement illustrated in FIG. 10, the cradle 1229 includes a resistance pad 1224 that is configured to permit the slight tilting of the body portion 1216.

In various instances, the resilient members 1228 have a different material composition than conductive elements 1215. In at least one example, the resilient members 1228 have a material composition that improves their ability to retain their resiliency overtime in comparison to the conductive elements 1215.

Unlike the conductive elements 1215, the resilient members 1228 need not be electrically conductive. In some examples, a resilient member 1228 can be made from one or more non-conductive materials. In addition, the resilient members 1228 may comprise a different spring rate than the conductive elements 1215. In some examples, a resilient member 1228 may comprise a spring rate greater than a conductive element 1215. Furthermore, as illustrated in FIGS. 10-13, a resilient member 1228 can be greater in size than a conductive element 1215.

In various examples, one or more conductors of a slip ring assembly of the present disclosure are covered with an external coating that is configured to minimize signal noise and/or loss of power/signals that can be caused by exposure of the conductors to water and/or other bodily fluids. For example, conductors 1205 of a slip ring or proximal connector flange 1201 can be covered with a layer or coating that is less conductive than the conductors 1205. Said another way, the coating may be more resistive than the conductors 1205.

In various examples, one or more of the conductors 1205 can be coated with a semi-conductive material including, for example, Carbon (C), Germanium (Ge), Silicon (S), Gallium arsenide (GaAs), and/or Silicon carbide (SiC) in order to reduce signal noise and/or loss of power/signals in water and/or other body fluids. In some examples, one or more of the conductors 1205 can be coated with a carbon ink or a silver ink. Alternatively, in other examples, the conductors 1205 can be fully made from a carbon ink or a silver ink. Any suitable carbon ink or silver ink can be utilized to make or coat the conductors 1205. In some examples, an ELECTRA D'OR™ ED5500 series Carbon conductor paste can be utilized to make or coat the conductors in order to reduce signal noise and/or loss of power/signals in water and/or other body fluids. The ED5500 is a range of carbon and silver/carbon conductive pastes. They are designed for high reliability applications where protection of metal contacts is required. Examples of other usable commercial conductive carbon ink include e.g. XZ302-1 HV and XZ302-1 MV conductive Carbon.

In various examples, one or more of the conductors 1205 can be coated, or otherwise covered, with an external coating or layer and an intermediate coating or layer closer to the conductors 1205 than the intermediate layer. The external layer can be less conductive than the intermediate layer. In at least one example, the external and intermediate layers can be comprised of non-conductive matrices that include conductive particles or fillers dispersed and/or embedded therein. In such examples, the density of the conductive particles in the intermediate layer is higher than the external layer. In result, the external layer possesses a higher resistivity than the intermediate layer which minimizes signal noise and/or loss of power/signals that can be caused by exposure of the conductors to water and/or other bodily fluids.

In various examples, one or more of the conductors 1205 are coated, or otherwise covered, with a compressible coating or layer. The compressible layer comprises a first conductivity in an uncompressed configuration and a second conductivity in a compressed configuration. In at least one example, the second conductivity is greater than the first conductivity. The first conductivity is sufficiently reduced to protect against any signal noise and/or loss of power/signals due to contact with water and/or other bodily fluid. In other words, the compressible layer or coating acts as a resistive layer or coating unless it is compressed. Once compressed, the compressible layer or coating becomes conductive to electricity only at the portion thereof that is compressed.

As illustrated in FIG. 12, the conductors or conductive elements 1215 are slightly biased when in contact with the conductors 1205. The resilient members 1228 may contribute to the biasing of the conductive elements 1215. When a conductor 1205 comprises a compressible layer, the biasing force applied by the conductive element 1215 may compress the compressible layer at a portion of the compressible layer in contact with the conductive element 1215. The compression applied by the conductive element 1215 may change the conductivity of the compressible layer at the compressed portion. In at least one example, the compression applied by the conductive elements 1215 may increase the conductivity of the compressible layer at the compressed portion. The conductivity of other portions of the compressible layer experiencing little or no compression may not change significantly.

As described above, the conductive elements 1215 are rotated with the commutator or distal connector flange 1211 relative to the proximal connector flange 1201 while contact is maintain, or at least substantially maintained, between the conductors 1205 and the conductive elements 1215 to transmit an electrical signal to and/or from the end effector 300. The rotation causes the conductive elements 1215 to transition from one compressed portion of the compressible layer to another, and the transmission of the electrical signal between the conductors 1205, 1215 is maintained at the compressed portions. The reduced conductivity of the uncompressed portions protects against any signal noise and/or loss of power/signals due to contact with water and/or other bodily fluid. Since the compressed portions are in direct contact with the conductive elements 1215, the compressed portions are also protected from the water and/or other bodily fluid.

In various examples, the slip ring assembly 1200 is configured to transmit energy to the end effector 300 to power, for example, an RF cartridge 1700 (FIG. 4). Such large currents when transmitted through loose connections may result in arcs and/or charring. However, coating a slip ring or proximal connector flange 1201 with a compressible layer, as described above, ensures that energy transmission occurs only when sufficient pressure is applied between the conductors 1205, 1215, which ensures a tight connection. Without the increased pressure, the compressible layer remains in a less conductive state that protects against arcs and/or charring.

The pressure applied to the compressible layer between the conductors 1205, 1215 controls the conductivity of the compressible layer. A higher pressure may correspond to a higher conductivity. In various examples, the pressure applied to a compressible layer between the conductors 1205, 1215 can be varied depending on the energy level of the electrical signal transmitted through the compressible layer. For example, a first pressure may be applied to the compressible layer during the transmission of a low-energy electrical signal such as, for example, an electrical signal carrying data; while a second pressure, higher than the first pressure, may be applied to the compressible layer during the transmission of a high-energy electrical signal such as, for example, an electrical signal configured to power the RF cartridge 1700 (FIG. 4).

In various examples, a sequence of operation of a surgical instrument 10 (FIG. 1) involves a number of steps. In some examples, the pressure applied to a compressible layer between the conductors 1205, 1215 can be varied depending on the step of operation of the surgical instrument 10. For example, a first pressure may be applied to the compressible layer during a closure step of operation; while a second pressure, higher than the first pressure, may be applied to the compressible layer during a firing step of operation.

Various techniques can be utilized to adjust the pressure applied to the compressible layer between the conductors 1205, 1215. In at least one example, referring to FIG. 12, the bracket member 1221 can be moved from a first position to a second position closer to the proximal connector flange 1201 to change the pressure applied to the compressible layer between the conductors 1205, 1215 from a first pressure to a second pressure higher than the first pressure, for example. In another example, a distal connector flange 1211 can be slightly tilted toward a proximal connector flange 1201 to change the pressure to the compressible layer between the conductors 1205, 1215. In yet another example, the proximal connector flange 1201 can be moved toward the distal connector flange 1211 to increase the pressure applied o the compressible layer between the conductors 1205, 1215.

Although various devices have been described herein in connection with certain embodiments, modifications and variations to those embodiments may be implemented. Particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Thus, the particular features, structures, or characteristics illustrated or described in connection with one embodiment may be combined in whole or in part, with the features, structures or characteristics of one ore more other embodiments without limitation. Also, where materials are disclosed for certain components, other materials may be used. Furthermore, according to various embodiments, a single component may be replaced by multiple components, and multiple components may be replaced by a single component, to perform a given function or functions. The foregoing description and following claims are intended to cover all such modification and variations.

The devices disclosed herein can be designed to be disposed of after a single use, or they can be designed to be used multiple times. In either case, however, a device can be reconditioned for reuse after at least one use. Reconditioning can include any combination of the steps including, but not limited to, the disassembly of the device, followed by cleaning or replacement of particular pieces of the device, and subsequent reassembly of the device. In particular, a reconditioning facility and/or surgical team can disassemble a device and, after cleaning and/or replacing particular parts of the device, the device can be reassembled for subsequent use. Those skilled in the art will appreciate that reconditioning of a device can utilize a variety of techniques for disassembly, cleaning/replacement, and reassembly. Use of such techniques, and the resulting reconditioned device, are all within the scope of the present application.

The devices disclosed herein may be processed before surgery. First, a new or used instrument may be obtained and, when necessary, cleaned. The instrument may then be sterilized. In one sterilization technique, the instrument is placed in a closed and sealed container, such as a plastic or TYVEK bag. The container and instrument may then be placed in a field of radiation that can penetrate the container, such as gamma radiation, x-rays, and/or high-energy electrons. The radiation may kill bacteria on the instrument and in the container. The sterilized instrument may then be stored in the sterile container. The sealed container may keep the instrument sterile until it is opened in a medical facility. A device may also be sterilized using any other technique known in the art, including but not limited to beta radiation, gamma radiation, ethylene oxide, plasma peroxide, and/or steam.

While this invention has been described as having exemplary designs, the present invention may be further modified within the spirit and scope of the disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles.

Any patent, publication, or other disclosure material, in whole or in part, that is said to be incorporated by reference herein is incorporated herein only to the extent that the incorporated materials do not conflict with existing definitions, statements, or other disclosure material set forth in this disclosure. As such, and to the extent necessary, the disclosure as explicitly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is said to be incorporated by reference herein, but which conflicts with existing definitions, statements, or other disclosure material set forth herein will only be incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material.

Various aspects of the subject matter described herein are set out in the following examples:

Example 1

A slip ring assembly for use with a surgical shaft assembly. The slip ring assembly comprises a first connector flange comprising a conductor, a second connector flange comprising a conductive element in contact with the conductor, and a support member. The second connector flange is rotatable relative to the first connector flange. The support member is configured to apply a load onto the second connector flange to maintain the contact between the conductor and the conductive element.

Example 2

The slip ring assembly of Example 1, wherein the conductive element applies a pressure against the conductor, and wherein the support member is further configured to maintain the pressure at or above a desired threshold.

Example 3

The slip ring assembly of one or more of Example 1 through Example 2, wherein the conductor is an annular conductor.

Example 4

The slip ring assembly of one or more of Example 1 through Example 3, wherein the conductive element comprises a spring contact.

Example 5

The slip ring assembly of one or more of Example 1 through Example 4, wherein the support member comprises a resilient member configured to apply the load onto the second connector flange.

Example 6

The slip ring assembly of Example 5, wherein the resilient member is a spring leaf.

Example 7

The slip ring assembly of one or more of Example 5 through Example 6, wherein the resilient member comprises a different material composition than the conductive element.

Example 8

The slip ring assembly of one or more of Example 5 through Example 7, wherein the resilient member comprises a different spring rate than the conductive element.

Example 9

A shaft assembly for use with a surgical instrument. The shaft assembly comprises a proximal shaft portion comprising a proximal connector that includes a plurality of conductors and a distal shaft portion. The distal shaft portion comprises a distal connector and a support member. The distal connector includes a plurality of conductive elements each in contact with one of the plurality of conductors, wherein the distal connector is rotatable relative to the proximal connector. The distal connector is positioned between the proximal connector and the support member, wherein the support member is configured to apply a load onto the distal connector to maintain the contact between the plurality of conductors and the plurality of conductive elements.

Example 10

The shaft assembly of Example 9, wherein the conductive elements apply a pressure against the conductors, and wherein the support member is further configured to maintain the pressure at or above a desired threshold.

Example 11

The shaft assembly of one or more of Example 9 through Example 10, wherein the conductors are annular concentric conductors.

Example 12

The shaft assembly of one or more of Example 9 through Example 11, wherein the conductive elements comprise spring contacts.

Example 13

The shaft assembly of one or more of Example 9 through Example 12, wherein the support member comprises a resilient member configured to apply the load onto the distal connector.

Example 14

The shaft assembly of Example 13, wherein the resilient member is a spring leaf.

Example 15

The shaft assembly of one or more of Example 13 through Example 14, wherein the resilient member comprises a different material composition than the conductive elements.

Example 16

The shaft assembly of one or more of Example 13 through Example 15, wherein the resilient member comprises a different spring rate than the conductive elements.

Example 17

A slip ring assembly for use with a surgical shaft assembly. The slip ring assembly comprises a slip ring comprising a conductor, a commutator, and a support member. The commutator comprises a commutator body portion and a commutator arm extending from the commutator body portion, wherein the commutator arm comprises a conductive element in contact with the conductor, and wherein the commutator is rotatable relative to the slip ring. The support member comprises a body portion including a cradle configured to receive and hold the commutator body portion and an arm extending from the body portion, wherein the arm comprises a resilient member configured to maintain the contact between the conductor and the conductive element.

Example 18

The slip ring assembly of Example 17, wherein the resilient member is a spring leaf.

Example 19

The slip ring assembly of one or more of Example 17 through Example 18, wherein the resilient member comprises a different material composition than the conductive element.

Example 20

The slip ring assembly of one or more of Example 17 through Example 19, wherein the resilient member comprises a different spring rate than the conductive element. 

The invention claimed is:
 1. A slip ring assembly for use with a surgical shaft assembly, the slip ring assembly comprising: a first connector flange comprising a conductor; a second connector flange comprising a conductive element in contact with the conductor, wherein the second connector flange is rotatable relative to the first connector flange; and a support member, wherein the second connector flange is sandwiched between the first connector flange and the support member, and wherein the support member comprises a slot configured to receive and hold the second connector flange and the support member is configured to apply a load onto the second connector flange to maintain the contact between the conductor and the conductive element.
 2. The slip ring assembly of claim 1, wherein the conductive element applies a pressure against the conductor, and wherein the support member is further configured to maintain the pressure at or above a desired threshold.
 3. The slip ring assembly of claim 1, wherein the conductor is an annular conductor.
 4. The slip ring assembly of claim 1, wherein the conductive element comprises a spring contact.
 5. The slip ring assembly of claim 1, wherein the support member comprises a resilient member configured to apply the load onto the second connector flange.
 6. The slip ring assembly of claim 5, wherein the resilient member is a spring leaf.
 7. The slip ring assembly of claim 5, wherein the resilient member comprises a different material composition than the conductive element.
 8. The slip ring assembly of claim 5, wherein the resilient member comprises a different spring rate than the conductive element.
 9. A shaft assembly for use with a surgical instrument, the shaft assembly comprising: a proximal shaft portion comprising a proximal connector that includes a plurality of conductors; and a distal shaft portion, comprising: a distal connector that includes a plurality of conductive elements each in contact with one of the plurality of conductors, wherein the distal connector is rotatable relative to the proximal connector; and a support member, wherein the distal connector is positioned between the proximal connector and the support member, and wherein the support member comprises a cradle configured to receive and hold the distal connector and the support member is configured to apply a load onto the distal connector to maintain the contact between the plurality of conductors and the plurality of conductive elements.
 10. The shaft assembly of claim 9, wherein the conductive elements apply a pressure against the conductors, and wherein the support member is further configured to maintain the pressure at or above a desired threshold.
 11. The shaft assembly of claim 9, wherein the conductors are annular concentric conductors.
 12. The shaft assembly of claim 9, wherein the conductive elements comprise spring contacts.
 13. The shaft assembly of claim 9, wherein the support member comprises a resilient member configured to apply the load onto the distal connector.
 14. The shaft assembly of claim 13, wherein the resilient member is a spring leaf.
 15. The shaft assembly of claim 13, wherein the resilient member comprises a different material composition than the conductive elements.
 16. The shaft assembly of claim 13, wherein the resilient member comprises a different spring rate than the conductive elements.
 17. A slip ring assembly for use with a surgical shaft assembly, the slip ring assembly comprising: a slip ring comprising a conductor; a commutator, comprising: a commutator body portion; and a commutator arm extending from the commutator body portion, wherein the commutator arm comprises a conductive element in contact with the conductor, and wherein the commutator is rotatable relative to the slip ring; and a support member, comprising: a body portion including a cradle configured to receive and hold the commutator body portion; and an arm extending from the body portion, wherein the arm comprises a resilient member configured to maintain the contact between the conductor and the conductive element.
 18. The slip ring assembly of claim 17, wherein the resilient member is a spring leaf.
 19. The slip ring assembly of claim 17, wherein the resilient member comprises a different material composition than the conductive element.
 20. The slip ring assembly of claim 17, wherein the resilient member comprises a different spring rate than the conductive element. 